1. Field of the Invention
The present invention relates to a mirror device for a vehicle.
2. Description of the Related Art
As a so-called door mirror provided outside of an occupant""s seat of a vehicle cabin, an electrically powered mirror device to be rotated by a motor""s driving force between a usage state, in which the reflection surface of a reflection mirror is directed substantially rearward of the vehicle, and a folded state, in which the same is directed substantially to the inside of the cabin in the vehicle width direction, can be presented (As an example thereof, see Japanese Patent Application Laid-Open (JP-A) No. 7-285380).
A vehicle mirror device of this kind, in general, has a motor case for accommodating a motor fixed on the vehicle body and rotatably supported by a cylindrical shaft provided upright from a stand. Furthermore, an adjusting actuator for adjusting the mirror surface angle of the reflection mirror is fixed to the motor case so that the reflection mirror is interlocked with the motor case via the adjusting actuator.
Moreover, an interlocking portion inside a substantially box-shaped or substantially bowl-shaped visor to be integrally interlocked with the visor is formed on the adjusting actuator. By interlocking the visor with the interlocking portion, the motor case, the adjusting actuator and the reflection mirror can be accommodated inside the visor.
The motor in the motor case is interlocked with a final gear provided integrally with the shaft via a speed reduction gearing. When electric power is supplied from a mounted battery to the motor via a harness provided in the shaft, the motor works to rotate the final gear by rotational force via the speed reduction gear. However, since the shaft with the final gear provided integrally is formed on the stand provided integrally with the vehicle body, the motor cannot rotate the final gear by its own driving force and so is rotated around the shaft by its own rotational force due to reaction force from the final gear. Thus, the motor case, the adjusting actuator, the visor and the reflection mirror are rotated integrally.
Since the vehicle mirror device is provided outside the vehicle cabin, in order to prevent entrance of rain water to the motor case, a cover is provided on the motor case for sealing an opening end of the motor case. Furthermore, prevention of entrance of rain water and the like into the motor case between the shaft""s outer circumference and the cover, by so-called faucet fitting of the cover at a distal end portion of the shaft, has been considered.
In the above-mentioned configuration, the motor case is rotatably supported by the shaft about a lower end of the shaft, and the cover is pivoted about the shaft at an upper end side of the shaft. If the cover is made of a relatively soft material, the cover may be distorted at the time of rotation around the shaft, and consequently backlash with respect to the shaft may be generated. When backlash is generated, substantially only the motor case is pivoted about the shaft lower end side, and thus smooth and appropriate rotation is difficult to execute.
In view of the above-mentioned problems, an object of the present invention is to obtain a mirror device for a vehicle capable of preventing entrance of water into a motor case, and capable of ensuring smooth and appropriate rotation of the motor case even when a soft material is used for a cover.
In order to achieve the above-mentioned object, according to one aspect of the present invention, there is provided an electrically powered foldable mirror device for a vehicle, the mirror device including: a substantially cylindrical shaft including an upper end portion with a hollow interior, and a lower end portion; a case including a first fitting portion fitting at the outer circumference of the shaft lower end portion for mounting the case to the shaft; a mirror main body directly or indirectly supported by the case; and a motor base mounted to the case and including a second fitting portion sealingly fitted with the shaft upper end portion such that the case and the motor base are rotatably supported along the vertical direction of the shaft by the first fitting portion and the second fitting portion, the second fitting portion including a first hole in fluid communication with the interior of the shaft upper end portion.